Piston ring



July 13 1926.

I. F. PFEIFFER PISTON RING 2. Sheet-Sheet 1 Filed Nov. 5, 1924 pm i fl.

' ATTORNEY July 13,1926. 1,592,704

I. F. PFEIFFER PISTON RING jlfilifk .ZTE'P e l en INVENTOR wn'nsssy a, I ATTORNEY Patented July 13, 19 26.

ISADORE F. IFEIFFER, F ALTOONA, PENNSYLVANIA.

rrsron RING.

7 Application filed November 3, 1924. Serial No. 747,610.

This invention relates to improvements in piston rings, the general object of the invention being to make the ring and groove of spiral shape so that the ring can be screwed onto'the piston without expanding the ring.

Another object of the invention is to provide means for holding the ring in the groove and to bridge a portion of the spiral space formed by the convolutions of the ring.

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claim. U

In describing my invention in detail, reference will be .had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which I Figure 1 is a view of a piston showing my improved ring thereon. V

. 2 is a section on line 22 of Figures Figure 3 is a top plan view with a part broken away. Figure 4 is a section on line 4-4 of Figure Figure 5 is a view of the ring itself. K Fig. 6 is a view of a modification.

Figure 7 is a section on line 77 of Figure 6. A

Figure 8 is a fragmentary edge view. Figure 9 is a diagrammatic view of the shown in these views, I form a spiral 40 vs in the iston A, the groove starting at the top of t e piston and extending to a point ad acent the skirt of the piston so that the groove is of considerable length.' The ring 2 is also of spiral shape and the ring is adapted to be placed in the groove by a 1'0- tary or screwing motion so that it is not necessaryto expand the ring over the piston as is now done with the split, rings. Thus the ring is not distorted in putting it on the piston. After the ring is in place a pin 3 1s placed in the upper part of the groove to ,prevent'the ring from workin out of the oove if the ring should breai. The ring 1s held in place and the space bridged by means of a plug 4 arranged in a recess 5 formed in the piston and having grooves in its head to receive the lower end of the ring and a part of one of the convolutions thereof. This plug projects sufiiciently to fill the space between the lower end of the ring and the next convolution thereof. The'ring is locked to the plu by means of a pin 6 which passes through the plug and through a recess 7 formed in the lower end of the ring. Figures 6, 7 and 8 show the invention applied to a steam piston, the ring being shown at 1 and the piston at A. In this case a wedge member 7 is driven into a dove-tail slot 8 formed in one wall of the piston, the wedge member having grooves 9 therein to receive the ring, the outside grooves being the same width as those in the piston, while the center groove 9' in the wedge, is less in width so as to receive, and hold tightly, the reduced portion 10 of the piston ring. This arrangement will prevent leakage between the ring and walls of the spiral groove as the groove in the piston is made slightly larger than this ring so as topermit expansion and contraction of the ring but the redued part 10 and the small groove 9 in the wedge member being arranged at the center, together with the weight of the pis-. ton acting downward, which effects a snug fitting joint between the inside face of rings and bottom of grooves in wedge, thereby effectually preventing leakage through the space between the ring and walls of the groove from either side of the piston. This arrangement of parts is clearly shown in Figure 8.

This form of ring will give high compression, the cylinder will wear round as the rin pressure is uniform, there is no danger of istorting the ring in putting it in place,

the ring can be made thicker which adds strength to it without interfering with its application" and the ring. is not liable to break as the split rings now in use. The stop pin and wedge member not only hold the ring in place but also prevent leakage" through the spiral space formed by the ring. In the locomotive application, the live steam entering the cylinder will carry oil around the spiral up to the wedge member, thereby oiling the cylinder walls ahead of the piston travel instead of oiling the walls after exhaust, as is now done.

The cycle it applying the steam ring is as followsr- Th ring is screwed in position 110 and the ring is then pulled away from the wedge receptacle, (this can be easily done because of the eccentricity of the groove), the wedge is driven in the piston an'd then the ring, home in the wedge.

Pistons using other style rings, that are of a design that will allow them to be reduced in diameter, can be so reduced, and a ring having within it a spiral groove, can be shrunk or otherwise fastened to theold piston, to allow the use of the spiral ring.

It is thought from the foregoing description that the advantages and novel features of my invention will be readily a parent.

I desire it to be understood t at I may make changes in the construction and in the combination and arrangement of the several parts, provided that such chan es fall within the scope of the appended c aim.

at the reduced section is driven formed in one piece and What I claim is In combination with a piston having a spiral groove in its circumference which starts at the top of the piston, a spiral ring fitting in the groove, said ring being adapted to be threaded in the groove by placing its lower end in the top part of the groove and giving it a rotary movement, said piston having a recess therein which communicates with several convolutionsrof the groove, a member fittin in said recess an having grooves therein receiving portions of a number. of

spirals of the ring for holding the ring in place and preventing leakage through the space formed by the rin and means for connecting the ring with t e member.

In testimony whereof I aflix my signature.

isanonn 1;. PFEIFFER. 

